FIGHTER PILOT (16K ZX81)
by C M Medley, Stapleford, Nottingham
from Your Computer (March 1982), Page 72

In this game you are a fighter pilot trying to repel an invasion by enemy
aircraft. You have a total of five aircraft armed with air-to-air missiles.
Each enemy plane shot down increments your score by one. Missed planes are
also counted. If you crash your aircraft into the enemy, or delay firing
too long and are caught in the blast of your own missile, you lose that
aircraft. Your score will include the aircraft brought down by collision.

Keys 6 and 7 manoeuvre the aircraft in the direction of the cursors, 0
fires the missile. As the program only tests whether a key is being pressed
once each cycle, the keys should be held down. The logic in line 130 is to
prevent an aircraft skipping over the missile. This program is written for
the ZX-81 with 16K RAM. However, if the frills are removed, you could use
the basic idea on a standard machine.
